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Resistance Formula:
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The resistance formula \( R = \rho \times \frac{L}{A} \) calculates the electrical resistance of a uniform conductor based on its material properties and physical dimensions. This fundamental equation in electrical engineering relates resistance to resistivity, length, and cross-sectional area.
The calculator uses the resistance formula:
Where:
Explanation: The formula shows that resistance is directly proportional to both resistivity and length, but inversely proportional to cross-sectional area.
Details: Accurate resistance calculation is crucial for designing electrical circuits, selecting appropriate wire sizes, predicting voltage drops, and ensuring proper functioning of electrical systems.
Tips: Enter resistivity in Ω·m, length in meters, and cross-sectional area in square meters. All values must be positive numbers greater than zero.
Q1: What is resistivity?
A: Resistivity is an intrinsic property of materials that quantifies how strongly they oppose electric current flow. It's measured in ohm-meters (Ω·m).
Q2: Why does resistance increase with length?
A: Longer conductors provide more obstacles for electrons to navigate, increasing the overall resistance to current flow.
Q3: Why does resistance decrease with larger cross-sectional area?
A: Larger cross-sectional areas provide more pathways for electrons to flow, reducing the overall resistance.
Q4: What are typical resistivity values?
A: Copper: ~1.68×10⁻⁸ Ω·m, Aluminum: ~2.82×10⁻⁸ Ω·m, Silver: ~1.59×10⁻⁸ Ω·m, Iron: ~1.0×10⁻⁷ Ω·m.
Q5: Does this formula apply to all materials?
A: This formula applies to uniform conductors with constant cross-section. For non-uniform or non-ohmic materials, more complex calculations are needed.